Puppy Love
by widerthandistance5647
Summary: A Christmas-related mishap reveals hidden crushes. Supercorp. Written based on a prompt by Leapyearbaby29: Kara got changed into a teenager around 14-15 and she has a crush on Lena. But she wasn't dating Lena yet before she was changed into a teen.
1. Chapter 1

Christmas was always Kara's favorite time of year. It had been from the moment she landed on Earth. Even Alex, who didn't like her at first, was nice to her during Christmas time. Christmas was just so full of goodness. Kara loves the idea of exchanging presents. That is perhaps her most favorite part of Christmas, although she certainly appreciates the excuse to eat as much food and sweets as possible.

Gift giving is special to Kara because it allows people to really demonstrate how much they love and appreciate each other. She still has the first present Alex ever gave her during her first Christmas on Earth - a Webster's dictionary. Eliza and Jeremiah had criticized Alex for the gift at first, after all, it was Alex's old dictionary. But Kara cherished it from the moment she opened it, because in it, Alex had inscribed, "Dear Kara, this book is to help you learn more about English. Maybe one day, you will know enough words to tell me about your life on Krypton. Maybe this book will help you discover more about my world. I have highlighted important words that you should know. Love, Alex." The book did help Kara learn more about the customs on Earth and more about Earth's history. Eventually, Kara was able to share some things about Krypton with Alex. And when Kara first became a reporter for CatCo, she brought her trusty dictionary with her.

And so, holding the tradition of gift-giving in the highest regard, Kara was now sneaking around the storage rooms of the DEO. This Christmas would be the first Christmas that Lena would be spending with Kara and the Superfriends. Having met Lillian a handful of times, none of which were pleasant, Kara could only imagine the types of Christmases that Lena had experienced in the past. And that did not make Kara happy. Lena was just so good and she deserved to the best Christmas ever. So Kara was searching for the perfect gift. A gift that would let Lena know how special she was. A gift that would show Lena just how much Kara cared about her.

The DEO has a special archive of items from Krypton. Kara rarely looked in the room the archive was stored in, because the first time she went in there, she was too overwhelmed with emotions and started bawling. Alex subsequently banned her from the room without supervision, and since Kara had had such a strong emotional reaction to seeing the stuff from her dead planet, she decided not to fight Alex on this issue. But this was a unique circumstance, and Kara had the perfect idea for a gift for Lena.

Unfortunately, with very limited space in the DEO compound, the Krypton stuff was stored with a bunch of other items from other planets and galaxies. Not all of these items had been properly tagged and some of them possessed properties that were mystical. And that is how, the night before Christmas Eve, Kara found herself reaching for a special necklace from Krypton and instead grabbing hold of a sphere from the planet Monorida. And, further, how the next morning, Alex found her sister in a storage room of the DEO as a very confused and scared fifteen year old.

* * *

"Kara!" Alex yelled, looking for her sister in the DEO. It was Christmas Eve and it was unlike Kara to disappear on the day before the most magical day of the year. Kara loved Christmas. And that is how Alex knew something was wrong.

When Kara didn't wake Alex up at 6 in the morning on Christmas Eve, as per Kara's rather annoying tradition, Alex became worried. Kara _always_ woke Alex up at 6 AM. 6 AM was when they began making Christmas cookies, only some of which were reserved for Santa, who Kara swore was real (Alex tried telling her that he was a myth, but then Kara said something about a different planet and since Kara was an alien and had special powers, Alex figured that maybe Kara was right), and made hot cocoa and watched really cheesy Christmas movies.

"Kara!" yelled Alex again. Since Kara wasn't at Alex's apartment, her older sister first looked at Kara's apartment. Upon not finding her there, she decided to look at the DEO. CatCo was closed, after all, and she couldn't think of anywhere else Kara could be. Plus, she had already called Lena and confirmed that Kara was not with her, although that just made the CEO worried, so Alex decided it would be best to find Kara _immediately,_ before the CEO started asking questions.

After fifteen minutes of searching all of the usual spots in the DEO, Alex heard a small voice whimpering. Following the sound, she eventually came to the storage room that Kara was in. Seeing which room it was, Alex was a little frustrated at her sister. She knew that Kara always felt a little lost during the holiday season, even though she loved it, because she wished she could share her new Earth traditions with her Kryptonian family. Which is why Alex had banned her from the Krypton room, especially during times of great emotion for Kara. And now Kara was locked in the room, crying.

But when Alex opened the door and instead of her twenty-four year old sister, she found a fifteen year old version of her sister, her eyes opened wide.

"Shit."

Kara stopped whimpering and looked at Alex with anxious eyes. "Who are you? You look familiar."

"I'm Alex, Kara, your sister."

"You're not Alex, but you do look kind of like her, if Alex was old. But Alex isn't my sister. Alex said she will never be my sister. You're lying! Who are you? I have powers, you know, I could hurt you."

 _Fuck,_ thought Alex. _She has memory loss, too, and damn, I was an ass to her as kids._

Raising her hands in a pacifying manner, Alex adopted her most reasonable tone of voice. "Kara, it really is me. and I'm sorry for saying that. But, look, something has happened to you. And I need to know what you did so I can fix it. How did you get here?"


	2. Chapter 2

After a moment of silence and no response, Alex asked again, "How did you get here, Kara?"

The younger version of Kara seemed to weigh her options, eventually answering, "I don't remember exactly. I woke up and I was here in this strange place with lots of things from Krypton."

Alex looked around and noticed again that they were in the Krypton storage room. Knowing how hard it was for older Kara to be in this room, she was struck with sudden sympathy for this younger version of her sister. But as much as she felt bad for Kara, she had to don her agent persona and get to the bottom of this. "Did you touch anything?"

Kara shook her head vigorously in denial, so Alex took a deep breath and tried to calm her sister down so that she could assess the room for any differences, which would be difficult given that the room wasn't well-organized to begin with. Maybe she would need to enlist help from Winn.

"Look, Kara," she said in her most soothing voice. "I know things don't make a lot of sense right now, but I am your sister Alex and I will protect you. You have to trust me. Do you think you can do that?"

Instead of seeming comforted, Kara looked at Alex in disbelief once more. "If you're really Alex, prove it. Tell me something that only you would know."

Alex smiled. She may not be her Kara exactly, but she also wasn't completely the young and trusting Kara she had been when she first landed. This was good. It meant that even with the apparent amnesia, present-day Kara still had some influence. "Superman is your cousin, Kal."

Kara gasped at that information. "Okay," she conceded, "maybe you are Alex. But if you're Alex, why are you so much older now?"

"Good question, and that's what I'm going to try to find out. Because, Kara, you're supposed to be a lot older too."

Now that Kara was at least a little calmed down and trusted Alex some, the DEO agent looked around the room. Nothing appeared to be out of place, so she texted Winn, thinking it best to get Kara away from the last remaining objects of a planet that was newly lost to her again. Once Winn confirmed he would be at the DEO momentarily to compare the contents of the room to the list on the archive, Alex told Kara it was time to leave.

"Where are we going?" asked Kara.

"Well, Kar, it's Christmas Eve, so we need to make Christmas cookies for our party later."

The mention of a party excited Kara and Alex was pleased that the girl seemed happy. Although on the way to the car, Alex had to remind Kara not to use her powers where people might see her.

* * *

The first three batches of Christmas cookies ended up being burnt to a crisp. Alex had forgotten the learning curve Kara and she had to go through before they perfected the art of Christmas baking, but Kara was having fun and that was what mattered. Alex was in the middle of singing along to the Christmas carols on the radio when Kara stopped mixing the cookie dough and looked at Alex with a funny expression.

"Someone's coming."

This obviously shocked Alex and she immediately went to agent mode right before the doorbell rang. Kara must have heard footsteps. Looking through the peephole, the brunette saw that on the other side was none other than Lena Luthor. Instead of being comforted that it wasn't some alien or person with nefarious purposes, Alex felt dread.

 _Oh shit, s_ he thought. _How am I going to explain this?_

Lena rang the doorbell again and Alex had no choice but to answer the door. After all, the Christmas music probably travelled through the thin door and Lena would know they were home.

Opening the door, Alex greeted the CEO, "Hey, Lena! What are you doing here?"

Lena looked a little confused at the question, or maybe confused because Alex opened the door and not Kara, "Hi, Alex, Kara invited me to bake cookies with you guys. When she learned that I didn't have many Christmas traditions of my own, she invited me to join yours. I hope that's not a problem."

"Oh, no, not at all!" said Alex. She really did like Lena now and she remembered Kara mentioning inviting Lena. It was just explaining to Lena, who still didn't know Kara was Supergirl, what happened and why Kara was suddenly fifteen.

Before Alex or Lena got to say anything more, however, the young Kara came over _much too fast_ for a regular human, Alex noted, and greeted the Luthor.

"Hi!" Kara said brightly, cutting in front of Alex and reaching for Lena's hand. "Are you a friend of Alex? Are you going to help us make cookies? We already started but Alex said the ones we made aren't any good so we are starting again! Come to the kitchen and I can show you what we have to do!"

With that, Kara pulled Lena into the kitchen, much to Lena's surprise and before she could answer any questions. Once in the kitchen, Kara started going over the instructions for cookie-making from a recipe Alex had written for her. But before she could get too far in her directions, Lena stopped her.

"I'm sorry, but who are you?" she asked as politely as she could.

"I'm Kara!" the blonde teenager said brightly, offering her flour-covered hand to shake Lena's.

"Ah, cousin," Alex tried to interject. "She's Kara's cousin. And mine. She's our cousin here for a visit." Alex attempted to send Kara some signals, saying she should play along with the story, but Kara was too busy staring at Lena. Alex rolled her eyes.

"You're pretty," Kara told Lena, blushing. "Who are you?"

"My name is Lena," the CEO said. "I'm Kara's friend. So you're her cousin? Kara never mentioned having younger cousins over for Christmas. I didn't realize this was a family affair."

The younger Luthor looked completely lost as to what to do, so Alex quickly jumped in, "It's okay, Lena, we didn't know that our cousin was going to come over until last minute. You aren't intruding. We love that you're here, don't we?"

"Yeah!" Kara exclaimed. "You can help me with my cookies."

"Hey, I thought I was helping you!" Alex said, partially offended but also wanting to distract Lena from the fact that Kara as she knew her wasn't there.

"Well," said Kara, "you can help too, but I want to work with my very pretty friend."

Lena blushed at the compliment, which she felt slightly odd about since it was given to her by a teenager. "Where's Kara though? Am I too early?"

"I'm right her-" Kara began saying before Alex cut her off.

"She's at CatCo working on a last minute article with James. She should be here soon, I think." _Or I hope,_ Alex thought.


End file.
